A Mobile Ad hoc NETwork (MANET) is a collection of wireless mobile hosts (computers, PDA's etc.,) connected by wireless links, forming a temporary network without any wireline infrastrucutre. The hosts are free to move randomly and organize themselves arbitarily resulting in rapid and unpredictable topology changes, in addition to it the wireless link subjects the signal to unpredictable environmental changes and hence provides only limited bandwidth. Due to the dynamic nature of the network topology and restricted resources, routing in MANET is a challenging task. Finding and maintaining the routes for multicasting the data is still more challenging. In this paper we propose Node transition probability based multicast routing algorithm (NTPMR) with coded route diversity technique to improve the packet delivery ratio for MANET. This algorithm uses multiple routes to transmit the data and code packet to all the members of the multicasting group. It is found that the proposed algorithm is most reliable in the sense that is uses only the best neighbors to transmit the data and also that is posses self healing nature that can overcome single route failure using 1 x N diversity code. The proposed algorithm is simulated using GloMoSIM and its Packet Delivery Ratio (PDR) performance with respect to mobility, number of multicast members in a group, number of nodes in a terrain range are studied. To understand the effectiveness of this algorithm, the performance results of single path, double path without coding are also presented. From the results, it is found that the coded route diversity techniques provides improved PDR.